If You See Window Bars with a Potbelly, This Is What It’s For

Updated: May 22, 2024

The window bars are for security—and the bump serves a purpose, too. Here's what we discovered.

If there’s one thing we love, it’s looking into mysterious old home features. Why do some houses from the ’50s have an extra little door in the hallway? Why do pre-World War II era homes have a toilet in the basement? And why do some apartments have window grilles with a bulge?

Reddit user u/lw1999 asked that exact question after coming across this kind of window grille. Of course, we were intrigued by this post too, so without further ado, let’s take a dive into why (and where) you might see these window bars.

Why Do Some Windows Have a “Potbelly”?

This style might be referred to as a “potbelly grille”  or  “window belly bars.” Some Reddit users thought that the bulge was for placing flower boxes. You can’t place a flower box on the rounded bars themselves, but you could extend one out from the windowsill.

Other Redditors argued that the bulges serve a a security purpose, since they’re often found only on the ground floor of buildings. New Yorkers argued that the bulge was for AC units!

So what’s the real story? According to this manufacturer, it’s… all of the above! Window grilles are usually installed on the ground floor for security purposes, keeping burglars from coming in. They’re often used for flower boxes, too. But whether you can fit an AC unit in them depend on the size of the window.

Where Can I Find Window Bars Like This?

You can often find them in Mediterranean and Latin countries. In the United States, look for them when you’re walking down the street in New York. Window grilles have a long history of being used in urban areas for security—and they double as ornamental ironwork. Certain cities, like New York, still have city codes requiring bars to be installed if a child under 10 lives in the residence. Whether the bars are straight or curved may depend on the builder.

If you ever move into an apartment with a “potbelly” in the window grille, you’ll know how to use it!